U.S. patent number 6,653,422 [Application Number 10/350,993] was granted by the patent office on 2003-11-25 for foldable ophthalmic and otorhinolaryngological device materials.
This patent grant is currently assigned to Alcon Universal Ltd.. Invention is credited to Charles Freeman, Douglas C. Schlueter.
United States Patent |
6,653,422 |
Freeman , et al. |
November 25, 2003 |
Foldable ophthalmic and otorhinolaryngological device materials
Abstract
Disclosed are soft, high refractive index, acrylic materials
having an elongation of at least 150%. These materials, especially
useful as intraocular lens materials, contain an aryl acrylic
hydrophobic monomer as the single principal device-forming monomer.
In addition to their use as intraocular lens materials, the present
materials are also suitable for use in other ophthalmic or
otorhinolaryngological devices, such as contact lenses,
keratoprostheses, corneal inlays or rings; otological ventilation
tubes and nasal implants.
Inventors: |
Freeman; Charles (Arlington,
TX), Schlueter; Douglas C. (Fort Worth, TX) |
Assignee: |
Alcon Universal Ltd.
(Hunenberg, CH)
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Family
ID: |
22543687 |
Appl.
No.: |
10/350,993 |
Filed: |
January 24, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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645669 |
Aug 23, 2000 |
6528602 |
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Current U.S.
Class: |
526/259;
623/6.11; 526/286; 526/292.5; 526/312; 526/319; 526/323.1; 526/328;
623/6.54; 526/323.2; 526/320; 526/313; 526/307.5; 526/292.3 |
Current CPC
Class: |
G02B
1/04 (20130101); A61L 27/16 (20130101); G02B
1/043 (20130101); C08F 220/30 (20130101); C08F
220/302 (20200201); C08F 220/301 (20200201); A61L
27/16 (20130101); A61F 11/00 (20130101); A61F
2/16 (20130101); C08L 33/16 (20130101); C08L
33/14 (20130101); G02B 1/04 (20130101); C08L
33/06 (20130101); G02B 1/043 (20130101); C08L
33/14 (20130101); A61L 27/16 (20130101); C08L
33/16 (20130101); A61L 27/16 (20130101); C08L
33/14 (20130101); A61F 2/16 (20130101); A61F
2/145 (20130101); A61F 2/14 (20130101) |
Current International
Class: |
A61L
27/16 (20060101); A61L 27/00 (20060101); C08F
220/00 (20060101); C08F 220/30 (20060101); G02B
1/04 (20060101); C08F 032/08 (); A61F 002/16 () |
Field of
Search: |
;623/6.11,6.54 ;351/159
;526/259,292.5,307.5,312,323.1,292.3,323.2,286,313,320 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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Oct 2000 |
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WO |
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WO 00/79312 |
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Dec 2000 |
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WO |
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Other References
Barrett, "A New Hydrogel Intraocular Lens Design," J. Cataract
Refract. Surg., vol. 20, pp. 18-25 (1994). .
Koch, D. Foldable Intraocular Lenses, slack Incorporated,
Thorofare, NJ (1993), Chapter 8, "Alcon AcrySof.RTM. Acrylic
Intraocular Lens," pp. 161-177. .
Koch, D. Foldable Intraocular Lenses, slack Incorporated,
Thorofare, NJ (1993), Chapter 8, "ORC MemoryLens.TM. A
Thermoplastic IOL," pp. 197-212. .
Sandner et al., "Die Medienabhangigkeit der alkalischen Hydrolyse
von Methylmethacrylat-Polymeren," Die Angewandte Makromolekulare
Chemie, vol. 115, pp. 207-219 (1983)..
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Primary Examiner: Zalukaeva; Tatyana
Attorney, Agent or Firm: Ryan; Patrick M.
Parent Case Text
This application is a continuation of U.S. Ser. No. 09/645,669,
filed Aug. 23, 2000, now U.S. Pat. No. 6,528,602 which claims
priority from U.S. Provisional Application, U.S. Ser. No.
60/152,622 filed Sep. 7, 1999.
Claims
We claim:
1. A polymeric ophthalmic or otorhinolaryngological device material
having an elongation of at least 150%, consisting essentially of a
single device-forming monomer and at least one cross-linking
monomer, optionally a reactive UV absorber and optionally a
reactive blue-light absorber, wherein the single device-forming
monomer is pr sent in an amount of at least about 80% by weight and
is an aryl acrylic hydrophobic monomer of the formula ##STR4##
wherein: A is CH.sub.3, C.sub.2 CH.sub.3, or CH.sub.2 OH; B is
(CH.sub.2).sub.m or(O(CH.sub.2).sub.2).sub.n ; m is 2-6; n is 1-10;
Y is nothing, O, S, or NR, provided that if Y is O, S, or NR, then
B is (CH.sub.2).sub.m ; R is H, CH.sub.3, C.sub.n H.sub.2n+1
(n=1-10), iso-OC.sub.3 H.sub.7, C.sub.6 H.sub.5, or CH.sub.2
C.sub.6 H.sub.5 ; w is 0-6, provided that m+w.ltoreq.8; and D is H,
C.sub.1 --C.sub.4 alkyl, C.sub.1 --C.sub.4 alkoxy, C.sub.6 H.sub.5,
or CH.sub.2 C.sub.6 H.sub.5, and provided that if combinations of
two or more types of cross-linking agents are used, none of the
cross-linking agents may be
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2 O).sub.n
--C(.dbd.O)C(CH.sub.3).dbd.CH.sub.2 wherein n=2-50.
2. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein A is CH.sub.3, B is (CH.sub.2).sub.m, m
is 2-5, Y is nothing or O, w is 0-1, and D is H.
3. The polymeric ophthalmic or otorhinolaryngological device
material of claim 2 wherein the aryl acrylic hydrophobic monomer is
selected from the group consisting of 4-phenylbutyl methacrylate;
5-phenylpentyl methacrylate; 2-benzyloxyethyl methacrylate; and
3-benzyloxypropyl methacrylate.
4. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 further comp sing one or more components
selected from the group consisting of reactive U absorbers and
reactive blue-light absorbers.
5. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the material is an ophthalmic device
material and has a refractive index of at least 1.50.
6. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the material has a Tg less than about
+25.degree. C.
7. The polymeric ophthalmic or otorhinolaryngological device
material of claim 6 wherein the material has a Tg less than about
+15.degree. C.
8. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the material has an elongation of at
least 200%.
9. The polymeric ophthalmic or otorhinolaryngological device
material of claim 8 wherein the copolymer has an elongation of at
least 300%.
10. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the device is selected from the group
consisting of contact lenses; keratoprostheses; corneal inlays or
rings; otological ventilation tubes; and nasal implants.
11. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the cross-linking component comprises
one or more cross-linking agents selected from the group consisting
of ethylene glycol dimethacrylate; diethylene glycol
dimethacrylate; allyl methacrylate; 1,3-propanediol dimethacrylate;
2,3-propanediol dimethacrylate; 1,6-hexanediol dimethacrylate;
1,4-butanediol dimethacrylate; CH.sub.2.dbd. C
CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2 O).sub.n
--C(O)C(CH.sub.3).dbd.CH.sub.2 where n=1--50; CH.sub.2.dbd.
C(CH.sub.3)C(.dbd.O)O(CH.sub.2).sub.t OC(.dbd.O)C(CH.sub.3)CH.sub.2
where t=3-20; and their corresponding acrylates provided that if
the device material comprises two or more cross-linking agents, one
of the cross-linking agents is
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2 O).sub.n
--C(.dbd.O)C(CH.sub.3)=CH.sub.2 wherein n=2-50.
12. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the sin e device-forming monomer is
present in an amount of at least about 85% by weight.
13. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the cross-linking monomer is present in
an amount of about 0.01-15% by weight.
14. The polymeric ophthalmic or otorhinolaryngological device
material of claim 1 wherein the aryl acrylic hydrophobic monomer is
selected from the group consisting of 4-phenylbutyl methacrylate;
5-phenylpentyl methacrylate; 2-benzyloxyethyl methacrylate; and
3-benzyloxypropyl methacrylate; and the cross-linking monomer is
CH.sub.2 .dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2 O).sub.n
--C(.dbd.O)C(CH.sub.3).dbd.CH.sub.2, where n is such that the
number average molecular weight of the cross-linking monomer is
about 1000.
15. An intraocular lens optic comprising the polymeric device
material of claim 1.
16. An intraocular lens optic comprising the polymeric device
material of claim 14.
Description
FIELD OF THE INVENTION
This invention is directed to acrylic device materials. In
particular, this invention relates to soft, high refractive index
acrylic device materials particularly suited for use as intraocular
lens ("IOL") materials.
BACKGROUND OF THE INVENTION
With the recent advances in small-incision cataract surgery,
increased emphasis has been placed on developing soft, foldable
materials suitable for use in artificial lenses. In general, these
materials fall into one of three categories: hydrogels, silicones,
and acrylics.
In general, hydrogel materials have a relatively low refractive
index, making them less desirable than other materials because of
the thicker lens optic necessary to achieve a given refractive
power. Silicone materials generally have a higher refractive index
than hydrogels, but tend to unfold explosively after being placed
in the eye in a folded position. Explosive unfolding can
potentially damage the corneal endothelium and/or rupture the
natural lens capsule. Acrylic materials are desirable because they
typically have a high refractive index and unfold more slowly or
controllably than silicone materials.
U.S. Pat. No. 5,290,892 discloses high refractive index, acrylic
materials suitable for use as an IOL material. These acrylic
materials contain, as principal components, two aryl acrylic
monomers. They also contain a cross-linking component. The IOLs
made of these acrylic materials can be rolled or folded for
insertion through small incisions.
U.S. Pat. No. 5,331,073 also discloses soft acrylic IOL materials.
These materials contain as principal components, two acrylic
monomers which are defined by the properties of their respective
homopolymers. The first monomer is defined as one in which its
homopolymer has a refractive index of at least about 1.50. The
second monomer is defined as one in which its homopolymer has a
glass transition temperature less than about 22.degree. C. These
IOL materials also contain a cross-linking component. Additionally,
these materials may optionally contain a fourth constituent,
different from the first three constituents, which is derived from
a hydrophilic monomer. These materials preferably have a total of
less than about 15% by weight of a hydrophilic component.
U.S. Pat. No. 5,693,095 discloses foldable ophthalmic lens
materials comprising a total of at least 90% by weight of only two
principal lens-forming monomers. One lens-forming monomer is an
aryl acrylic hydrophobic monomer. The other lens-forming monomer is
a hydrophilic monomer. The lens materials also comprise a
cross-linking monomer and optionally comprise a UV absorber,
polymerization initiators, reactive UV absorbers and reactive
blue-light absorbers.
SUMMARY OF THE INVENTION
Improved soft, foldable acrylic materials which are particularly
suited for use as IOLs, but which are also useful as other
ophthalmic or otorhinoloaryngological devices, such as contact
lenses, keratoprostheses, corneal rings or inlays, otological
ventilation tubes and nasal implants have now been discovered.
These materials contain only one principal lens-forming component:
an aryl acrylic hydrophobic monomer. The materials of the present
invention comprise at least about 80% by weight of the principal
monomeric component. The remainder of the material comprises a
cross-linking monomer and optionally one or more additional
components selected from the group consisting of UV-light absorbing
compounds and blue-light absorbing compounds.
Among other factors, the present invention is based on the finding
that acrylic copolymers suitable for use as foldable IOL materials
can be synthesized using only one principal aryl acrylic
hydrophobic monomer, reducing or eliminating difficulties, such as
physico/chemical heterogeneity, associated with curing copolymers
that contain two or more principal device-forming monomers.
DETAILED DESCRIPTION OF THE INVENTION
The ophthalmic or otorhinolaryngological device materials of the
present invention comprise only one principal device-forming
monomer. For convenience, the device-forming monomer may be
referred to as a lens-forming monomer, particularly with reference
to an IOL. The materials of the present invention, however, are
also suitable for use as other ophthalmic or otorhinolaryngological
devices such as contact lenses, keratoprostheses, corneal inlays or
rings, otological ventilation tubes and nasal implants.
The aryl acrylic hydrophobic monomers suitable for use as the sole
lens-forming monomer in the materials of the present invention have
the formula ##STR1##
wherein: A is H, CH.sub.3, CH.sub.2 CH.sub.3, or CH.sub.2 OH;
B is (CH.sub.2).sub.m or [O(CH.sub.2).sub.2 ].sub.n ;
C is (CH.sub.2).sub.w ;
m is 2-6;
n is 1-10;
Y is nothing, O, S, or NR, provided that if Y is O, S, or NR, then
B is (CH.sub.2).sub.m ;
R is H, CH.sub.3, C.sub.n H.sub.2n+1 (n=1-10), iso-OC.sub.3
H.sub.7, C.sub.6 H.sub.5, or CH.sub.2 C.sub.6 H.sub.5 ;
w is 0-6, provided that m+w.ltoreq.8; and
D is H, C.sub.1 --C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.6
H.sub.5, CH.sub.2 C.sub.6 H.sub.5 or halogen.
Preferred aryl acrylic hydrophobic monomers for use in the
materials of the present invention are those wherein A is CH.sub.3,
B is (CH.sub.2)m, m is 2-5, Y is nothing or O, w is 0-1, and D is
H. Most preferred are 4-phenylbutyl methacrylate, 5-phenylpentyl
methacrylate, 2-benzyloxyethyl methacrylate, and 3-benzyloxypropyl
methacrylate.
Monomers of structure I can be made by known methods. For example,
the conjugate alcohol of the desired monomer can be combined in a
reaction vessel with methyl methacrylate, tetrabutyl titanate
(catalyst), and a polymerization inhibitor such as 4-benzyloxy
phenol. The vessel can then be heated to facilitate the reaction
and distill off the reaction by-products to drive the reaction to
completion. Alternative synthesis schemes involve adding
methacrylic acid to the conjugate alcohol and catalyzing with a
carbodiimide or mixing the conjugate alcohol with methacryloyl
chloride and a base such as pyridine or triethylamine.
The materials of the present invention comprise a total of at least
about 80%, preferably at least about 85%, by weight or more of the
principal lens-forming monomer.
The copolymer materials of the present invention are cross-linked.
The copolymerizable cross-linking agent used in the copolymers of
this invention may be any terminally ethylenically unsaturated
compound having more than one unsaturated group. Suitable
cross-linking agents include, for example: ethylene glycol
dimethacrylate; diethylene glycol dimethacrylate; allyl
methacrylate; 1,3-propanediol dimethacrylate; 2,3-propanediol
dimethacrylate; 1,6-hexanediol dimethacrylate; 1,4-butanediol
dimethacrylate; CH.sub.2 =C(CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2
O).sub.n --C(.dbd.O)C(CH.sub.3).dbd.CH.sub.2 where n=1-50; and
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O(CH.sub.2).sub.t
O--C(.dbd.O)C(CH.sub.3)=CH.sub.2 where t=3-20; and their
corresponding acrylates. The most preferred cross-linking monomer
is CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2 O).sub.n
--C(.dbd.O)C(CH.sub.3).dbd.CH.sub.2 where n is such that the
number-average molecular weight is about 400, about 600, or, most
preferably, about 1000.
The chosen cross-linking agent should be soluble in the chosen
monomer of structure I to minimize curing problems. When n
approaches the upper end of the range of 1-50, the
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2 O).sub.n
--C(.dbd.O)C(CH.sub.3).dbd.CH.sub.2 cross-linker may not be soluble
at desired levels in some monomers of structure I even with the aid
of heat or sonication.
Generally, only one cross-linking monomer will be present in the
device materials of the present invention. In some cases, however,
combinations of cross-linking monomers may be desirable. If
combinations of two or more types of cross-linking agents are used,
none of the cross-linking agents may be
CH.sub.2.dbd.C(CH.sub.3)C(.dbd.O)O--(CH.sub.2 CH.sub.2 O).sub.n
--C(.dbd.O)C(CH.sub.3).dbd.CH.sub.2 wherein n=2-50.
Generally, the total amount of the cross-linking component is at
least 0.1% by weight and, depending on the identity and
concentration of the remaining components and the desired physical
properties, can range to about 20% by weight. The preferred
concentration range for the cross-linking component is 0.1-15% by
weight.
In addition to the aryl acrylic hydrophobic lens-forming monomer
and the cross-linking component, the lens material of the present
invention may also contain a total of up to about 10% by weight of
additional components which serve other purposes, such as reactive
UV and/or blue-light absorbers.
A preferred reactive UV absorber is
2-(2'-hydroxy-3'-methallyl-5'-methylphenyl)benzotriazole,
commercially available as o-Methallyl Tinuvin P ("oMTP") from
Polysciences, Inc., Warrington, Pa. UV absorbers are typically
present in an amount from about 0.1-5% (weight).
Suitable reactive blue-light absorbing compounds are those
described in U.S. Pat. No. 5,470,932, the entire contents of which
are hereby incorporated by reference. Blue-light absorbers are
typically present in an amount from about 0.01-0.5% (weight).
Suitable polymerization initiators include thermal initiators and
photoinitiators. Preferred thermal initiators include peroxy
free-radical initiators, such as t-butyl (peroxy-2-ethyl)hexanoate
and di-(tert-butylcyclohexyl) peroxydicarbonate (commercially
available as Perkadoxe.RTM. from Akzo Chemicals Inc., Chicago,
Ill.). Particularly in cases where the lens material does not
contain a blue-light absorbing chromophore, preferred
photoinitiators include benzoylphosphine oxide photoinitiators,
such as the blue-light initiator
2,4,6-trimethyl-benzoyidiphenylphosphine oxide, commercially
available as Lucirin.RTM. TPO from BASF Corporation (Charlotte,
N.C.). Initiators are typically present in an amount of about 5%
(weight) or less.
The identity and amount of the principal lens-forming monomer
described above and the identity and amount of any additional
components are determined by the desired properties of the finished
ophthalmic lens. Preferably, the ingredients and their proportion
are selected so that the acrylic lens materials of the present
invention possess the following properties, which make the
materials of the present invention particularly suitable for use in
IOLs which are to be inserted through incisions of 5 mm or
less.
The lens material preferably has a refractive index in the dry
state of at least about 1.50 as measured by an Abbe' refractometer
at 589 nm (Na light source). For a given optic diameter, optics
made from materials having a refractive index lower than 1.50 are
necessarily thicker than optics of the same power which are made
from materials having a higher refractive index. As such, IOL
optics made from materials having a refractive index lower than
about 1.50 generally require relatively larger incisions for IOL
implantation.
The glass-transition temperature ("Tg") of the lens material, which
affects the material's folding and unfolding characteristics, is
preferably below about 25.degree. C., and more preferably below
about 15.degree. C. Tg is measured by differential scanning
calorimetry at 10.degree. C./min., and is determined at the
midpoint of the transition of the heat flux curve.
The lens material will have an elongation of at least 150%,
preferably at least 200%, and most preferably at least 300%. This
property indicates that the lens generally will not crack, tear or
split when folded. Elongation of polymer samples is determined on
dumbbell shaped tension test specimens with a 20 mm total length,
length in the grip area of 4.88 mm, overall width of 2.49 mm, 0.833
mm width of the narrow section, a fillet radius of 8.83 mm, and a
thickness of 0.9 mm. Testing is performed on samples at standard
laboratory conditions of 23.+-.2.degree. C. and 50.+-.5% relative
humidity using a tensile tester. The grip distance is set at 14 mm
and a crosshead speed is set at 500 mm/minute and the sample is
pulled to failure. The elongation (strain) is reported as a
fraction of the displacement at failure to the original grip
distance. The modulus is calculated as the instantaneous slope of
the stress-strain curve at a selected strain. Stress is calculated
at the maximum load for the sample, typically the load when the
sample breaks, assuming that the initial area remains constant.
This stress is recorded as "tensile strength" in the examples
below.
IOLs constructed of the materials of the present invention can be
of any design capable of being rolled or folded into a small cross
section that can fit through a relatively smaller incision. For
example, the IOLs can be of what is known as a one piece or
multipiece design, and comprise optic and haptic components. The
optic is that portion which serves as the lens. The haptics are
attached to the optic and hold the optic in its proper place in the
eye. The optic and haptic(s) can be of the same or different
material. A multipiece lens is so called because the optic and the
haptic(s) are made separately and then the haptics are attached to
the optic. In a single piece lens, the optic and the haptics are
formed out of one piece of material. Depending on the material, the
haptics are then cut, or lathed, out of the material to produce the
IOL.
The invention will be further illustrated by the following
examples, which are intended to be illustrative, but not limiting.
Example 1: Synthesis of 4-phenylbutyl methacrylate. ##STR2##
A three neck round bottom flask containing a teflon coated magnetic
stirring bar was successively charged with 120 mL (1.09 mol) of
methyl methacrylate (2), 5.35 g (0.015 mol) of titanium
tetrabutoxide (Ti(OC.sub.4 H.sub.9).sub.4), 60 mL (0.39 mol) of
4-phenyl-1-butanol (1), and 14.6 g (0.073 mol) of 4-benzyloxyphenol
(4-BOP). An addition funnel, thermometer, and a short path still
head with thermometer and receiver flask were placed in the flask
necks. The flask was placed in an oil bath and the temperature was
increased until distillation began. Methyl methacrylate (2) was
placed in the addition funnel and was added dropwise at the same
rate as the distillate. The reaction mixture was heated for 4 hours
and then cooled to room temperature. The crude product was vacuum
distilled to isolate 62.8 g (0.29 mol, 74%) of 4-phenylbutyl
methacrylate (3) as a clear, colorless liquid. Example 2: Synthesis
of 3-benzyloxypropyl methacrylate. ##STR3##
A three neck round bottom flask containing a teflon coated magnetic
stirring bar was successively charged with 95 mL (0.884 mol) of
methyl methacrylate (2), 4.22 g (0.012 mol) of titanium
tetrabutoxide (Ti(OC.sub.4 H.sub.9).sub.4), 50 mL (0.316 mol) of
3-benzyloxy-1-propanol (1), and 14.6 g (0.073 mol) of
4-benzyloxyphenol (4-BOP). An addition funnel, thermometer, and a
short path still head with thermometer and receiver flask were
placed in the flask necks. The flask was placed in an oil bath and
the temperature was increased until distillation began. Methyl
methacrylate (2) was placed in the addition funnel and was added
dropwise at the same rate as the distillate. The reaction mixture
was heated for 4 hours and then cooled to room temperature. The
crude product was vacuum distilled to isolate 36.5 g (0.156 mol,
49%) of 3-benzyloxypropyl methacrylate (3) as a clear, colorless
liquid.
Examples 3-29, shown below in Tables 1-4, illustrate of the
materials of the present invention. Each of the formulations of
Examples 3-29 are prepared as follows. After combining the
formulation components as listed in Tables 1-4, each formulation is
mixed by agitation and then injected into a polypropylene
25.times.12.times.1 mm slab mold. To make slabs, the cavity in the
bottom portion of the slab mold is filled to capacity with the
formulation and then the top is placed on strictly as a seal. The
molds can either be filled under an inert nitrogen or standard
laboratory atmosphere. To maintain the mold geometry during curing,
spring clamps are used on the molds. The clamped molds are placed
in a forced air oven and cured by heating to 70-80.degree. C.,
holding at 70-80.degree. C. for one hour, then heating to
approximately 100-110.degree. C. and holding at approximately
100-110.degree. C. for two hours. At the end of polymerization
period, the molds are opened and the cured intraocular lenses or
polymer slabs are removed and extracted in acetone to remove any
materials not bound to the cross-linked network.
Physical property data shown for the cured materials in Tables 1-4
were assessed (according to the methods referred to above). Unless
indicated otherwise, all ingredient amounts shown below are listed
as % by weight. The following abbreviations are used in Tables
1-4:
PEMA: 2-phenylethyl methacrylate
PPrMA: 3-phenylpropylmethacrylate
PBMA: 4-phenylbutylmethacrylate
BEEMA: benzyloxyethoxyethyl methacrylate
BEMA: 2-benzyloxyethyl methacrylate
BPMA: 3-benzyloxypropyl methacrylate
PPMA: 5-phenylpentyl methacrylate
BBMA: 4-benzyloxybutyl methacrylate
PEO 1000: polyethylene glycol 1000 dimethacrylate
PEO 600: polyethylene glycol 600 dimethacrylate
PEO 400: polyethylene glyclo 400 dimethacrylate
EGDMA: ethylene glycoldimethacrylate
t-BPO: t-butyl (peroxy-2-ethyl)hexanoate
BPO: benzoyl peroxide
TABLE 1 Example Tg No. PEMA PPrMA PBMA PEO 1000 EGDMA t-BPO %
Elongation (.degree. C.) 3 85 15 1 304 -- 4 99 1 1 172 15 5 85 15 1
753 -10 6 99 1 1 583 0 7 85 15 1 619 -24
TABLE 2 Examples Component 8 9 10 11 12 13 14 BEMA -- -- -- -- --
89.9 -- PBMA -- -- -- -- -- -- 90.0 BPMA 94.7 90 -- 99.6 -- -- --
PPMA -- -- 89.7 -- -- -- -- BBMA -- -- -- -- 89.9 -- -- PEO 1000
5.3 10 10.3 -- 10.1 10.1 10.1 EGDMA -- -- -- 0.4 -- -- -- t-BPO 1.4
1.5 1.4 1.6 1.6 1.3 1.4 Tensile strength 3.37 2.83 2.02 3.07 1.11
6.46 4.195 (MPa) % Strain 900 659 515 974 440 815 696 Young's
modulus 0.67 0.62 0.76 1.02 0.33 1.89 2.00 (MPa) 100% modulus (MPa)
0.45 0.42 0.51 0.59 0.22 1.07 0.99 RI (dry) 1.539 1.534 1.533 1.543
1.531 1.541 1.535
TABLE 3 Examples Component 15 16 17 18 19 20 21 22 23 PBMA 89.75
85.02 79.97 94.95 89.82 85.03 94.99 89.89 84.96 PEO 400 10.25 14.98
20.03 -- -- -- -- -- -- PEO 600 -- -- -- 5.05 10.18 14.97 -- -- --
PEO 1000 -- -- -- -- -- -- 5.01 10.11 15.04 BPO 0.98 0.96 0.95 0.98
0.95 0.96 1.04 0.95 0.97 Tensile Strength (MPA) 8.23 8.6 8.74 6.55
6.33 514 6.17 5.62 4.35 % Strain 444 378 325 881 707 562 1051 875
699 Young's 6.59 5.78 5.56 3.85 2.82 1.77 4.05 1.92 1.24 modulus
(MPA) 100% modulus 3.47 3.34 3.32 2.28 1.55 1.12 2.06 1.12 0.77
(MPA) Tg(.degree. C.) 5 4 -1 -1 -5 -- -- -- --
TABLE 4 Examples (Ingredients shown in % w/w) Component 24 25 26 27
28 29 30 31 BEEMA -- -- -- -- -- -- 99.6 90.0 PPrMA 85.03 -- --
85.00 -- -- -- -- PBMA -- 85.02 -- -- 84.94 -- -- -- PPMA -- --
85.06 -- -- 85.00 -- -- PEO 600 14.97 14.98 14.94 -- -- -- -- --
PEO 1000 -- -- -- 15.00 15.06 15.00 -- 10.0 EGDMA -- -- -- -- -- --
0.6 -- BPO 1.00 1.01 0.99 1.01 1.01 1.01 -- -- t-BPO -- -- -- -- --
-- 1.1 1.2 Tensile 8.34 4.24 2.67 6.15 3.35 2.05 1.56 1.22 Strength
(MPA) % Strain 502 486 390 662 582 402 468 294 Youngs (MPA) 5.48
1.38 0.85 2.41 0.88 0.67 0.32 0.51 100% (MPA) 3.09 0.96 0.57 1.41
0.63 0.48 0.24 0.36 Tg (.degree. C.) -- -- -- -- -- -- -23.2
-26.7
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